Ingredient

Lanolin

The best thing there is for cracked nipples and split, chapped lips. It is also one of the better-known contact allergens, and both of those things are true at once.
At a Glance

Lanolin is the waxy grease sheep produce to waterproof their wool, purified and used as a heavy moisturizer. It is unusually good at two specific jobs: cracked nipples in breastfeeding, where it is the standard recommendation, and lips that are genuinely split rather than just dry. It seals like petrolatum but is stickier and clings better to wet skin. The catch is allergy — lanolin is a recognized contact allergen and sits on standard patch test panels. Modern medical-grade lanolin is far more purified than older versions, and reactions are less common than the reputation suggests.

Key Facts

What It IsA purified wax-like grease from sheep's wool, used as a heavy occlusive moisturizer
Best ForCracked nipples in breastfeeding, severely chapped and split lips, cracked fingertips and heels, dry eyelids
Typical StrengthSold nearly pure (100% lanolin) or as a few percent in ointments, lip balms and nipple creams
Rx RequiredNo
Cost$8-$15 for a tube of purified nipple cream or lanolin lip ointment. Plain lanolin in a jar is cheaper

How It Works

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Lanolin is not an oil and not a true fat. It is a wax ester mixture — the grease sheep secrete to keep rain out of their wool — and its structure is closer to the natural lipids in human skin surface than most plant butters are.

Two properties make it useful. First, it is strongly occlusive: a film of lanolin dramatically slows water evaporating out of the skin, which is what lets a split, dehydrated crack in the lip or nipple actually close. Second, it is emulsifying — lanolin can hold several times its own weight in water. That means it does not slide off damp or weeping skin the way a pure grease does, and it can help keep a healing crack moist rather than scabbed over. This is why it beats plain petrolatum in the two places it is famous for.

It has no active pharmacology. It does not kill bacteria, reduce inflammation or speed healing directly. It creates the moist environment in which skin heals faster on its own.

What It Treats

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Moderate evidence
Lanolin seals lips well and is also a recognised lip allergen. It is on the standard patch test panel for exactly this reason.
Limited evidence
Lanolin is a strong occlusive and works well on cracked hands, but it is a recognised contact allergen and is included in standard patch test series.

How to Use It

For cracked nipples
  • Apply purified lanolin after each feed, on clean skin, in a thin layer that you do not rub in. It does not need to be washed off before the next feed — the modern purified grades are made for exactly this, and the amount a baby could take in is negligible. Use it as a moist-healing dressing over the crack, not as a treatment for the cause. Cracked nipples almost always come from a latch problem, and lanolin will keep failing until the latch is fixed. Get a feeding assessment alongside it.
For chapped and split lips
  • A thick layer at night is the version that works. Lanolin is sticky enough to stay put for hours, which is the whole point — most lip balms are gone within twenty minutes. Reapply during the day as needed. If the problem is lip eczema or a lip-licking habit, lanolin protects the skin while the habit is broken.
For cracked fingertips and heels
  • Apply at night and cover — a cotton glove or sock. Occlusion overnight is what closes fissures. Combining it with a keratolytic like urea during the day works better than either alone on thick heel skin.

Pairing & Conflicts

What to pair it with

Urea or lactic acid on thickened heel and fingertip skin, during the day, with lanolin at night. One thins the hard scale, the other seals.

A saline rinse and air-drying between feeds, for cracked nipples. Lanolin plus letting the skin dry between applications works better than lanolin alone.

Topical steroids in lip eczema or hand dermatitis, applied first and given time to absorb, with lanolin over the top or later in the day.

Petrolatum as the fallback if you cannot tolerate lanolin. It seals nearly as well, does not cling to damp skin as well, and almost never causes allergy.

What not to mix

Do not put lanolin on skin that is red, weeping and getting worse, in case that reaction is to the lanolin itself. Stop and reassess rather than layering more products over it.

Do not use it under an occlusive dressing on infected skin. Sealing an infection in is how a small problem becomes a bigger one.

Do not combine it with a fragranced lip product if your lips are already irritated. When lips flare, the usual culprits are fragrance, flavoring, propolis, sunscreen filters and lanolin — and using several at once makes it impossible to tell which.

There is no chemical incompatibility with actives. Lanolin is inert. But like any heavy occlusive it increases how much of an underlying retinoid or acid gets absorbed, so do not seal over one unless you mean to.

Side Effects

Most people use lanolin without any trouble. The one side effect that genuinely matters is allergy.

Common and expected
  • A sticky, tacky feel that some people dislike.A faint sheepy or waxy smell, more noticeable in cheaper grades. Greasy marks on pillowcases and clothing. Mild stinging when first applied to an open crack. Clogged pores if used on acne-prone facial skin. Lanolin is heavy.
Tell your doctor
  • An itchy, scaly, spreading rash where you applied it, especially one that appears after several days of use rather than immediately. That delayed pattern is classic allergic contact dermatitis, and lanolin is one of the substances standard patch test panels screen for.Lips that get worse the more balm you apply. This is a common trap — the balm becomes the cause and the reflex is to use more of it. A leg ulcer or long-standing eczema patch that is not healing under a lanolin-containing dressing. Allergy rates are higher on chronically damaged skin. Nipple pain that is not improving, or that is burning and deep rather than surface cracking. That may be thrush or a latch problem rather than dryness.
Stop and get care
  • Spreading redness, warmth, swelling or pus around a nipple crack or a fissure. That is infection, and in breastfeeding it can become mastitis quickly.Facial or eyelid swelling, or a blistering rash. Any rash that keeps spreading beyond where the product was applied.

Who Should Avoid It

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Do not use it if you have a known lanolin or wool alcohol allergy. This is the one hard rule. It appears on ingredient lists under several names — lanolin, lanolin alcohol, wool alcohols, wool wax, Amerchol, Eucerit — and it is present in a great many ordinary creams and ointments, so people with the allergy have to read labels carefully.

Be cautious if you have long-standing stasis dermatitis or a chronic leg ulcer. Skin that has been inflamed for years becomes sensitized to topical ingredients far more readily, and lanolin allergy is meaningfully more common in this group. Many wound clinics avoid it for that reason.

Skip it on acne-prone facial skin. It is heavy and it clogs.

Do not use it on wounds you suspect are infected.

On the allergy question generally. Lanolin has an outsized reputation as an allergen, built partly on older, cruder material. In people with normal skin, reactions to modern purified lanolin are uncommon. In people with damaged skin who apply it repeatedly over months, they are much less uncommon. Both statements are true, and which one applies depends on which group you are in.

Breastfeeding. Purified lanolin is the standard recommendation and does not need to be wiped off before feeding. If your baby develops a rash around the mouth, stop and change products.

Vegans may want to know it is an animal product, though the sheep are shorn rather than harmed.

How Long Until It Works

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Hours
Lips stop feeling tight and raw almost immediately. That is the seal, not healing.
Two to three days
A split lip or a cracked nipple that is being kept continuously moist starts to close. Kept moist beats letting it scab — a scab cracks open again with every feed or every smile.
Five to ten days
Most simple cracks are closed if the cause has also been dealt with. For nipples, that means the latch. For lips, that means stopping the licking. For fingertips, that means gloves for wet work.
Two to four weeks
Thickened, fissured heels and fingertips improve with nightly use under occlusion. This is the slowest use.
If nothing has improved in two weeks,
the diagnosis is probably wrong. Persistently cracked lips can be lip eczema, an allergy to something else in your routine, or angular cheilitis at the corners, which is usually yeast and needs an antifungal. Persistent nipple pain can be thrush or vasospasm. More lanolin will not fix any of those.
When you stop
Skin that has healed stays healed if the cause is gone. If the cause is still there — the latch, the licking, the wet work — cracking returns within days. Lanolin is a dressing, not a cure.
FAQ+
Do I need to wash lanolin off before breastfeeding?No. Modern purified nipple creams are made to be left on, and the amount a baby swallows is trivial. Older advice to wipe it off came from less purified material.
Is lanolin better than petrolatum for cracked lips?For lips that are genuinely split, usually yes. Lanolin holds water and clings to damp skin, so it keeps a crack moist rather than just coated. Petrolatum is the better choice if you are allergic to lanolin or if the stickiness bothers you.
Is lanolin allergy common?Common enough to be on standard patch test panels, uncommon enough that most people use it with no problem. The risk is much higher in people applying it repeatedly to already damaged skin — chronic leg ulcers and long-standing eczema in particular — than in someone using a lip balm.
Is modern lanolin different from old lanolin?Yes, meaningfully. Medical-grade lanolin is refined to remove the free alcohols and pesticide residues that caused much of the historic problem. Cheap, industrial and veterinary lanolin has not been through that.
Can lanolin make my chapped lips worse?It can, in two ways. If you are allergic to it, the lips get progressively worse the more you apply, which feels like needing more balm. And if the real problem is lip eczema or a fungal infection at the corners of the mouth, no balm will help. If two weeks of lanolin has made no difference, stop and get it looked at.
Does lanolin clog pores?On acne-prone facial skin, yes. Keep it for lips, hands, heels and nipples.
Is lanolin vegan?No. It is a sheep product, though it is collected from shorn wool rather than from the animal directly. Petrolatum and shea butter are the usual vegan substitutes, and neither clings to damp skin as well.
Can I use it on my eyelids?Yes, and it is useful for dry, flaking eyelid dermatitis — the eyelid skin is thin and tolerates a bland occlusive well. If the eyelids are what is inflamed, though, lanolin is also one of the ingredients worth suspecting.
Will lanolin heal a cracked nipple on its own?No. It keeps the crack moist so it can close, which speeds healing considerably. It does nothing about the latch that caused it, and that is the part that decides whether the crack comes back.